The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
During the operation of power electronic devices, heat is generated as a result of the current that flows through the devices. Effectively dissipating the heat that is produced during the operation of electronic devices is an important concern in optimizing the performance and ensuring the longevity of the components and circuitry that are integral to such devices.
Heat dissipation is particularly important in the case of high power electronic devices. One such example is a belt alternator system used in hybrid vehicles. Batteries and power electronics associated with belt alternator starter systems are capable of delivering and receiving as much as 10 kW of peak electrical power, necessitating the use of auxiliary cooling devices for the batteries and the power electronics.
Where auxiliary cooling is desired for the proper operation of an electronic device, heat sinks can be attached to the heat-producing electronic devices in a thermally conductive manner to absorb heat generated by the electronic device and efficiently transfer the heat to its surroundings. Accordingly, heat sinks are formed of a material having a high thermal conductivity, usually a metallic material. Many heat sinks include extended surfaces, such as fins, to increase the heat transfer rate from the electronic device to its surroundings by increasing the effective surface area of the heat sink. Furthermore, ambient air can be forced along the extended surface of a heat sink to further increase the heat transfer rate of the heat sink.
Heat sink performance can be negatively affected in a variety of ways. Heat sinks made from metallic substances can corrode due to exposure to heat, moisture, and corrosives present in the ambient air. Corrosive layers that form on the surface of a heat sink are generally thermally insulating in comparison to the base material and inhibit the transfer of heat from the heat sink to its surroundings. Additionally, contaminants present in the ambient air, such as dust and dirt, can attach or collect on the surface of a heat sink and form thermally insulating layers.
Heat sink performance can degrade to a point that heat generated by the electronic device is not sufficiently dissipated to the device's surroundings and excessive heat will build within the electronic device, leading to elevated operating temperatures. Elevated operating temperatures may result in degraded performance of the electronic device or damage to the electronic device.